Microprocessors are found in almost every electronic device that we use in our day-to-day lives. One important application of microprocessors has been in the control of electronic devices installed in vehicles, including automobiles, buses, and airplanes. In the past, many critical automobile functions have been accomplished mechanically. Automobile functions such as wheel differential adjustments and engine timing are now controlled using sensors and actuators electrically connected to microprocessors.
Microprocessors provide well-known advantages, including making diagnostics and repairs easier in complicated machines. Microprocessors have also been used to improve the efficiency of machines when used with sensors and actuators in a feedback loop, thereby obtaining more efficient modes of operation. There are, however, some disadvantages to the use of microprocessors.
A look under the hood of a newer automobile may be enough to see one disadvantage to microprocessor use. Before microprocessors became small enough and reliable enough to be installed in automobiles, it was possible to see how separate engine parts were connected, and even to see the road underneath. Nowadays engine parts are covered by wires and cables that run from sensors and actuators attached to the mechanical parts to microprocessors used for control. Extra wires and cables are disadvantageous: every extra wire installed consumes power and adds weight. More wires also make maintenance harder.
Unfortunately, it has been largely impossible for wires to be eliminated from most microprocessor system designs. Conventionally, a separate wire has been required for power, ground, and each of a plurality of data transmission lines between a microprocessor and one or more sensors or actuators attached thereto.
U.S. Pat. No. 6,906,618, which was granted to the present inventors in 2005 and is herein incorporated by reference, discloses a method and system for bidirectional power and data transmission. The disclosed method and system reduce the number of wires used in power and data systems.
A continued need exists however for further improvements to conventional power and data systems.